Supplementary Material for: Management and Clinical Outcomes of Membranous Nephropathy, IgA Nephropathy, and Minimal Change Disease Two Years Post-Kidney Biopsy

Introduction This study evaluated the phenotypic and pathology characteristics of patients undergoing kidney biopsy at a single center, while also determining the frequency and factors associated with clinical outcomes. Methods The incidence and distribution of biopsy-proven kidney diseases in 2000-2019 were surveyed. Consecutive individuals diagnosed with membranous nephropathy (MN), immunoglobulin A nephropathy (IgAN), and minimal change disease (MCD) between August 2015 and December 2019 were enrolled in the prospective two-year follow-up study. Outcomes included remission of proteinuria and kidney disease progression events. Multivariable adjusted Cox proportional hazards model was applied. Results 4,550 kidney biopsies were performed in 2000–2019, showing a noticeable increase in the proportion of MN. 426 patients were enrolled in follow-up cohort. 346 (81.2%) achieved remission of proteinuria, 39 (9.2%) suffered kidney disease progression and 51.3% of them were diagnosed with IgAN. Kidney pathological diagnosis (MN vs. MCD: hazard ratio [HR], 0.42; 95% confidence interval [95% CI], 0.31–0.57; IgAN vs. MCD: 0.58; 0.39–0.85), levels of 24-h urine protein at biopsy (1.04; 1.00–1.08) and presence of nodular mesangial sclerosis (0.70; 0.49–0.99) were significantly correlated with remission of proteinuria after adjusting for baseline variables. 24-h urine protein levels at biopsy (1.14; 1.04–1.25) and the presence of crescents (2.30; 1.06–4.95) were the independent risk factors for kidney disease progression events after adjusting for baseline variables. Conclusion The increasing frequency of MN was affirmed over the past two decades. The therapeutic status, clinical outcomes, and factors influencing these outcomes were presented in this single-center study for the three primary glomerular diseases. Number of China Clinical Trial Registry: ChiCTR2100043001.

引言 本研究旨在评估单中心肾活检患者的表型与病理特征，并明确临床结局的发生频率及其相关影响因素。
研究方法 本研究首先调查了2000年至2019年间经活检证实的肾脏疾病的发病率与分布特征。同时纳入2015年8月至2019年12月期间连续确诊的膜性肾病（membranous nephropathy, MN）、免疫球蛋白A肾病（immunoglobulin A nephropathy, IgAN）及微小病变肾病（minimal change disease, MCD）患者，开展为期两年的前瞻性队列随访研究。本次研究的结局指标包括蛋白尿缓解与肾脏病进展事件，数据分析采用多变量校正Cox比例风险模型。
研究结果 2000年至2019年间，本中心共完成4550例次肾活检，结果显示膜性肾病（MN）的占比呈显著上升趋势。本研究共纳入426例患者进入随访队列。其中346例（81.2%）达到蛋白尿缓解，39例（9.2%）发生肾脏病进展；队列中有51.3%的患者被诊断为免疫球蛋白A肾病（IgAN）。在校正基线变量后开展的多因素分析显示：肾脏病理诊断（膜性肾病 vs 微小病变肾病：风险比（hazard ratio, HR）=0.42，95%置信区间（95% confidence interval, 95% CI）=0.31~0.57；免疫球蛋白A肾病 vs 微小病变肾病：HR=0.58，95% CI=0.39~0.85）、活检时24小时尿蛋白定量水平（HR=1.04，95% CI=1.00~1.08）以及系膜结节性硬化（HR=0.70，95% CI=0.49~0.99）均与蛋白尿缓解显著相关。此外，在校正基线变量后，活检时24小时尿蛋白定量水平（HR=1.14，95% CI=1.04~1.25）与新月体形成（HR=2.30，95% CI=1.06~4.95）是肾脏病进展事件的独立危险因素。
研究结论 本研究证实了过去二十年间膜性肾病的发病率呈上升趋势。本项单中心研究针对三种原发性肾小球疾病，明确了其诊疗现状、临床结局以及影响临床结局的相关因素。本研究在中国临床试验注册中心的注册号为：ChiCTR2100043001。